


Omnia Causa Fiunt

by DoubleSunday



Series: Forever and A Day [1]
Category: Undertale (Video Game)
Genre: Assistant Sans, Good W. D. Gaster, M/M, Pre-Accident W. D. Gaster, Scientist Sans (Undertale), Scientist W. D. Gaster, Younger Brother Papyrus (Undertale)
Language: English
Status: In-Progress
Published: 2021-03-07
Updated: 2021-03-10
Packaged: 2021-03-12 23:01:33
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 6,155
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29891871
Author URL: https://archiveofourown.org/users/DoubleSunday/pseuds/DoubleSunday
Summary: Gaster has been working alone for his whole time as the royal scientist, Asgore notices that it's been taking a toll on him and does him a favor by getting him an assistant. Sans is struggling to raise his younger brother and desperately needs a job to keep a roof over their heads, he sees an opportunity that he can't resist when Asgore starts looking for an assiant for the royal scientist.
Relationships: W. D. Gaster/Sans
Series: Forever and A Day [1]
Series URL: https://archiveofourown.org/series/2197839
Comments: 14
Kudos: 21





	1. Chapter 1

**Author's Note:**

> Omina Causa Fiunt- Everything happens for a reason

“Sire I’m telling you, I don’t need any help.” Gaster said following the taller monster through the lab.

“You can’t do all this work on your own Gaster.” Asgore said at the door of the lab, “I worry about you my friend…”

Gaster pouted slightly as his shoulders slumped in defeat, after a moment he straightened up and regained his usual composure. He had to remind himself, just because Asgore was his friend didn’t mean that he could act so childish. 

“Sire, I wouldn’t even know where to begin looking for an assistant.” He said, “It’s not like many monsters are looking to go into the field of science.”

“That’s perfectly fine.” Asgore said as the door opened for him.

“It is?” Gaster asked, hopeful that this would discourage the king. 

“Of course, I’ve already found one for you.” Asgore said, stepping out of the lab, “He starts later today.”

And with that the door shut, leaving Gaster gapping in awe at his friend’s boldness. After a moment he walked back to his desk and sat down, he put his head in his hands trying to clear his head. He didn’t want an assistant, he didn’t want to have to interact with anyone, he didn’t want to have to share his space with anyone. The lab was his safe space, a place where he wouldn’t have to worry about other people. Now he would have to share his safe space with a complete stranger, and what if they didn’t get along? What if his new assistant hated him or he hated his assistant? A million questions ran through his head as he tried to focus on his work, to say he didn’t get much work done would be an understatement. He went on like this for a few hours until he heard a small knock come from the main door of the lab, he took in a deep breath and stood up to walk to let his new assistant in. As he came to the door he took in another deep breath and composed himself and looked straight ahead, he was surprised when he didn’t see anyone.

“Hey, Dr. W. D. Gaster, right?” A voice came from below, he looked down to see a small skeleton in a blue hoodie and basketball shorts. A relaxed grin sat on his face as he looked up at Gaster, “I’m Sans, Sans the Skeleton.”

“I’m sorry, did you need something?” Gaster asked in a serious tone.

“I’m your new assistant.” Sans said.

Gaster went silent. There was no way that this was his new assistant, Asgore couldn’t be that desperate to find someone. The skeleton was hardly dressed for the job! This was already shaping up to be an awful idea on Asgore’s side.  
“You’re joking, right?” Gaster asked.

“Nope, was hired by Asgore a few days ago.”

“What are your qualifications?”

“Don’t really got any.” Sans shrugged.

“Did you even finish highschool?”

“Never went.”

“Never went to highschool?”

“Never went to school.”

Gaster went silent again. What in the world was Asgore thinking!? Here was an uneducated rando with no real reason to be here besides Asgore telling him to be.

“This all has to be some kind of joke that Asgore decided would be funny, you have no qualifications for this job.” Gaster temples in frustration, “You aren’t even dressed properly.”

“Listen,” Sans started, Gaster looked at him, “Give me a chance, I’ll show you why Asgore chose me.”

Gaster looked away and thought for a moment, there was no real reason that he should take his offer. He could always tell Asgore that this was a bad idea, but then again he would just tell Gaster to give the skeleton a chance anyway. Gaster let out a small sigh.

“Fine, I’ll give you one week to show me why I should keep you around.”


	2. Chapter 2

Spending a week with Sans was already shaping up to be an interesting experience, Sans was certainly an interesting assistant to have around. Any work that was thrown his way would be done very fast, it seemed like any challenge that would be thrown his way would be met with ease. All of that would be fine if it wasn’t for the fact that it seemed that Sans was doing the bare minimum, he would get his work done quickly and then spend the rest of the day sleeping while Gaster continued to do his work. Sans would often be on his phone if he wasn’t sleeping, that annoyed Gaster to no end. He wished that Sans would at least offer to help him, you know, like an assistant should. He wouldn’t call Sans lazy, lazy would imply that he didn’t get his work done. No Gaster would say that Sans is a minimalist, and that wasn’t always a great thing to be.

“Dr. Gaster?” Came Sans’ voice from his desk, “I’m going on break now.”

‘You’ve pretty much been on break since 10am’ Gaster thought to himself as he watched Sans get up from his desk and take off his lab coat. Gaster looked back to his work and gave an unamused hum of approval and Sans was off walking to the main door. 

Once Gaster heard the door close he put his head in his hands and let out a sigh, he didn’t know how to feel about Sans. Sans was definitely proving himself, but Gaster didn’t personally like him. It’s not like he could just go to Asgore and say: “I don’t like him so get rid of him”, that would just be childish of him and unfair to Sans. He wiped his face and got up from his desk, he needed to clear his head before getting back to more paperwork. He took the elevator down to the true lab, maybe he could do something down there while Sans was out.

-

Sans stepped out of the crushing atmosphere of the lab and out into the scorching heat of Hotland, he pulled out his phone and searched through his contacts before stopping on one name: Papyrus.

Sans: hey bro, i’m taking my lunch break now

Sans: want me to come home and make you something?

Papyrus: NO BROTHER THAT’S OK

Papyrus: THE NICE BOY FROM THE BAR CAME TO GIVE ME SOMETHING TO EAT ALREADY

Sans: ok bro 

Sans: call me if you need anything then

With that Sans put away his phone and started to walk farther into Hotland, he could probably find somewhere cheap to eat. As he walked around he found a nice shop that sold small snacks, he bought a couple of food items from the shop and noticed they offered hot chocolate.

“Oh! Admiring our hot chocolate?” The shop owner, a tall plant-like bug, asked sweetly, “We’re having a sale on them today, or well, it’s every Wednesday but you get what I mean.”

“Alright, what’s the deal then?” Sans asked.

“Buy one, get one free.” They smiled, “Share a cup with someone you care about, or someone that you’d like to get to know.”

Sans thought for a moment and pulled out some more G, “I’ll take one.”

-

Sans ate most of his snacks on his way back to the lab and drank most of his hot chocolate, as he entered the lab he began to feel full so he decided to stop eating. He sat down at his desk and threw away his trash into his deskside trash can, he looked at the rest of his food and extra hot chocolate. He decided against eating and drinking the other drink, he didn’t want them to go to waste though. He looked over to the empty desk that Gaster would usually be occupying, only to notice that the doctor wasn’t there but his large stack of paperwork sat there unattended. He got up from his desk and placed a few lava cookies that he had left on the middle of the desk and placed the full hot chocolate near them, he gave a quick glance at the stack of paperwork that Gaster had to do.

-

Gaster exited the elevator and stepped out to the main floor of the lab, he walked back to his desk only to notice that Sans was now working again. He looked at his pile of paperwork only to notice that most of it was gone and now on Sans’ desk, he also noticed some cookies and a cup of unknown liquid on his desk.

“Hey doc.” Sans waved at him, “Thought you could use a little help.”

Gaster slightly cringed at the use of ‘doc’ but he still gave a small smile to the skeleton, “Ah, thank you Sans.”

Gaster took a seat at his desk and took the cup into his hand, he placed it to his lips and took a small sip. Hot chocolate, his favorite. He took one of the cookies into his hand and took a bite, they tasted quite good. He ate his food in silence and then continued his work for the rest of the day.

-  
It was time to leave by the time both of them had finished their work for the day, and for the first time, Gaster and Sans walked out of the lab together. Sans turned to Gaster giving him a genuine smile.

“First time I’ve seen you actually leave this place doc.” Sans laughed.

Gaster rolled his eyes, “I suppose it is.”

They fell into silence.

“You don’t really talk much, do you doc?”

“No.” Gaster said simply, “And I’d prefer if you didn’t call me that.”

Sans fought the urge to roll his eyes at his boss, “Then what should I call you, Dr. Gaster is a bit much ain’t it?”

“I prefer you keep things formal.”

Sans stiffened up, “Fine, if that’s what you want.”

Gaster began to walk away but gave one last call to Sans, “ We’re going to be working on more hands on things tomorrow, so be prepared.”


	3. Chapter 3

Sans closed the front door and took his shoes off at the door, he didn’t want Papyrus complaining about him tracking snow through the house. He was just about to sit down on the couch when Papyrus came bounding down the stairs and launched into him with a hug.

“HELLO BROTHER.” Papyrus looked up at him while still hugging him tightly, “WELCOME HOME.”

“Hey Papyrus, you have fun today?” He smiled down at his brother.

“YES.” Papyrus smiled back and let go of him, “THE BOY FROM THE BAR ATE WITH ME TODAY BEFORE HE HAD TO GO BACK AND HELP HIS FATHER.”

Sans sat down on the couch and closed his eyes for a moment, just simply content.

“DID YOU HAVE A GOOD DAY BROTHER?” Papyrus asked, “WHAT IS IT LIKE WORKING WITH THE DOCTOR?”

Sans opened his eyes again and looked at Papyrus, who stood there looking at his brother with a hopeful smile. How does he even begin to describe his boss to Papyrus? Cold and unfeeling? Sans hummed, thinking for a moment.

“I don’t think he likes me very much.” Sans said simply, getting up off the couch, “You hungry bro?”

“WHAT?” Papyrus asked, frowning slightly, “WHAT DO YOU MEAN HE DOESN’T LIKE YOU?”

“He doesn’t like me, simple as that.” Sans started to walk to the kitchen, “We got any leftovers?”

“WHAT GIVES YOU THE IDEA THAT HE DOESN’T LIKE YOU?” Papyrus followed behind his brother, “EVERYONE LIKES YOU!”

‘People tolerate me, they don’t like me’ Sans thought to himself slightly frowning.

“He and I have barely spoken a word since we met, and most of that was him criticizing me.” Sans said opening the refrigerator, “Not much tonight huh?”

“THEN HOW DO YOU KNOW HE DOESN’T LIKE YOU?” Papyrus asked, “IF YOU TWO HAVEN’T TALKED THEN HE MIGHT JUST BE SHY.”

“I doubt that bro, he doesn’t like me and that’s that.” Sans said, “Just leave it at that bro.”

Papyrus deflated and became saddened. Sans looked at his brother with a sympathetic look on his face.

“You ok with mac and cheese tonight?” Sans smiled at him.

Papyrus nodded sadly. 

-

Gaster had just gotten home and settled down for a bit when started to get a call.

“Hello?” Gaster asked.

“Hello my friend!” Asgore’s voice came through, “I’m sorry we haven’t talked in a few days, I’ve been a bit busy these last few days.”

“Ah, that’s quite alright sire.” Gaster said getting up.

“So how have you been my friend?”

“I’ve been fine, work is as it usually is.” Gaster rummaged through his refrigerator for a bit.

“I see, so how is Sans then?” 

Gaster stiffened at the mention of his assistant, should he tell Asgore about his gripes toward the skeleton? 

“He’s… fine.” Gaster said, pulling back from his refrigerator with a small container.

“That wasn’t very convincing Gaster.” Asgore said, sounding slightly upset, “Is there a problem with him?”

“Just some mannerisms that I don’t particularly like about him.” Gaster opened the container and placed it in his microwave to heat up.

“I’m sorry.” Asgore said softly, “Would you like for me to find you a new assistant?”

Gaster went silent, did he really want someone else new to intrude into his space? Not to mention that Sans got his work done, he couldn’t guarantee that from someone else. Still he thought.

“No sire, I don’t think that will be necessary.” Gaster said as the microwave beeped, “He’s a good worker, that wouldn’t be fair for him.”

“Your feelings on the matter are important too.” Asgore said.

“So are his.” Gaster said sitting down with his lasagna.  
Asgore went silent for a moment, “That’s very mature of you my friend.”

“Thank you sire.” Gaster smiled.

“I’ll leave you to the rest of your night.” Asgore said, “Tell me if you need anything more.”

“Goodnight Asgore.”

“Goodnight Gaster.”

Asgore hung up and Gaster was left in silence. He stared down at his food, not really feeling hungry anymore, now he just felt a familiar loneliness that he always felt. He put the top back on the container and put it back in the refrigerator, he then started to walk up to his room. He took a quick shower and laid down in bed, maybe Toriel was right when she said that he needed more friends.


	4. Chapter 4

Sans and Gaster were down in the true lab, they were working on one of Gaster’s projects. Sans had no idea what the things were supposed to be just that they were supposed to generate some kind of beam from what he could gather, they were still in the beginning stages of development. The two sat in a suffocating silence as Gaster led the project, that’s when Sans remembered what his brother had told him before he left this morning:

“JUST PLEASE TRY TALKING TO HIM TODAY BROTHER,” Papyrus pouted, “GIVE HIM A REASON TO LIKE YOU”

Those words nagged at him, he took a deep breath and looked over to his boss. Gaster was currently doing god knows what with the project as Sans just stood there, he let out his breath ready to give it a shot.

“So, Dr. Gaster.” Sans started, “What exactly is this project?”

Surprisingly, Gaster actually looked over at him. The doctor paused for a moment before speaking.

“These are simply going to be the prototypes.” Gaster started, “But the idea is that they use magic as their energy like any other attack would.”

“So they’re a new attack?” Sans asked, getting closer to look at the small skull, “What for?”

“The plan is to make a larger one that’s powerful enough to break the barrier.” Gaster said looking back to the blaster in front of him.

“Anything I can help with?” 

Gaster stilled, he hadn’t had any luck with his magic in trying to activate the blaster. Maybe what he needed was a different power source? 

“Perhaps there is.” Gaster fully turned to look at Sans, “How does your magic manifest?”

-

After a few trials and errors Gaster had finally discovered that Sans’ magic manifested in his eyes, and it was very powerful. Gaster had hooked up Sans’ left eye to the blaster.

“Doctor, are you sure this is gonna work?” Sans said shakily, he was afraid to admit that he was a bit scared.

“It’s simply a hypothesis,” Gaster admitted while focusing on connecting the blaster, “But if it works then we may have just found out the key to getting the blasters to work.”

Sans couldn’t lie, the use of ‘we’ made his heart skip a little. This would be the first time that he would be helping to create something useful.

“Ok, Sans.” Gaster looked up at his assistant, “Now all I need you to do is focus your magic, focus it into your eye specifically.”

Sans did as he was told and suddenly the blaster started to move, pupils appeared in it’s eye sockets and it began to float off the table that it was on. Sans and Gaster stared at it in shock, suddenly Gaster broke out into a laugh.

“Uh, you ok doc?” Sans asked.

“It works Sans!” Gaster grinned wildly, “It finally works!”

Gaster was quick to separate the connections from the blaster to see if it would continue to work, the blaster stared at him while he took off the connections. The blaster continued to move around freely, looked around the room before locking eyes with Sans. The small blaster flew over to hover by Sans’ head as it stared at Gaster with what looked to be fear, Gaster tried to get close to it but it made an ungodly noise at him as it charged up a small blast. Gaster got hit with the blast but it did very little damage to him, not even enough to ruffle him a bit. 

“Woah!” Sans said, getting away from the blaster, “You ok doc?”

“I’m fine, it hardly did any damage to me.” Gaster said, he thought for a moment, “Sans could you try to get closer to the blaster?”

“After that? Are you crazy?” Sans looked at Gaster with panic in his eyes.

“I simply would like to test something.” Gaster said, backing away.

Sans looked over at the blaster and took a deep breath, he outstretched a hand towards the blaster and slowly came closer to it until it nuzzled against his hand. Sans relaxed and pulled the blaster closer to him, it sat comfortably between his hands as it stared up at Sans.

“Hey there little buddy.” Sans smiled at it.

“That’s amazing.” Gaster breathed out, “Because it’s connected to your magic it trusts you, that’s why it attacked me. I'm unfamiliar.”

“Guess that’s kinda cool.” Sans rubbed a thumb over the smooth skull.

“This is quite something.” Gaster said to himself whilst rubbing his chin, “It’s bonded with him through his magic, almost as if it’s a part of him now.”

Sans happily petted the blaster who seemed to enjoy the attention, he was starting to like this little guy.

“Ah, Sans.” Gaster said, breaking his focus on the blaster, “Let me take the connections off of your eye.”

Sans had completely forgotten about the wires on his eye, he let got of the blaster and walked over to the doctor.

“Right.” Sans said lifting his head up to the doctor, “Thanks doc.”

“Dr. Gaster.”

“Right, thank you Dr. Gaster.”

Just as Gaster was about to reach for Sans’s eye, the blaster came up and blocked him. It sat in between Gaster and Sans’ eye, threatening to shoot at him again.

“Sans?” Gaster pulled his hand back, “Could you do something about the blaster? It seems to trust you.”

“Uh, yeah.” Sans put a hand on the blaster, “Hey buddy, the doctor ain’t gonna hurt me he just wants to help me out.”

The blaster turned to look at him and went to hover on top of his head, still watching Gaster in an attempt to seem intimidating. Gaster just shrugged it off and carefully removed the wires from Sans’ eye. Once the wires were removed Gaster announced that they should pack up for the day, seeing as they had made a lot of progress on the blasters today. The two of them walked out of the lab together with the blaster in tow.

“So what’d we call it?” Sans asked.

“Hm?” Gaster hummed, “Call what?”

“The blaster.” Sans said, “Not like we can just keep calling it ‘the blaster’, gotta have a name.”

“That’s unnecessary.” Gaster said, “The blaster doesn’t need a name, it’s a weapon not a pet.”

“Still wouldn’t hurt to call it something.”

Gaster let out a sigh and turned to start his walk to his house, “Call it what you like, it makes no difference to me.”

Sans frowned a little and looked at the blaster, gesturing for the blaster to come closer, “Come on buddy.”

The blaster snuggled up against him and Sans teleported them back to the front door of his house, he walked into the house and took off his shoes like usual.

“Papyrus I’m back!” Sans called out for his brother, “And I brought a new friend!”

**Notes for the Chapter:**

> I think of Gaster blasters to be a bit like dogs, they can be very kind but they're a bit wary of people that they don't know.


	5. Chapter 5

It was almost three weeks since Sans had started working with Gaster, and yet he was still having trouble breaking through his shell. Usually Sans could just talk to someone and make a joke then they would like him, but with Gaster it was so much harder. Sans hadn’t even wanted to joke with him because of how serious the man acted, he was constantly afraid that it was one wrong move and he’s gone. He couldn’t afford that, not when he and Papyrus had just started living somewhat decently. The way that he sees it, Gaster tolerates him and he wanted to keep it that way when the possibility of his job being on the line was at stake.

“Sans, are you ready to leave?” Gaster’s voice came through, interrupting his thought process, “I’d rather not keep King Asgore waiting.”

That’s right, they had a meeting with Asgore today to talk about their progress on current projects. He didn’t know much about what they were doing but at least he liked Asgore, the old goat could appreciate a good joke. Sans got up wordlessly from his desk and began to follow Gaster out of the lab and began to follow him to New Home, eventually they made it to the throne room. Asgore wasn’t there yet so the two of them basically stood around and did nothing, in an awkward silence. Gaster didn’t like this silence, it felt uncomfortable to him that his assistant had hardly even made an attempt to talk to him today. The usually talkative skeleton was now staring off into space, just ignoring Gaster. Gaster decided to clear his throat.

“So, how has the blaster been?” Gaster asked looking down at Sans.

“Hm?” Sans hummed coming out of his own thoughts, “Oh, you mean buddy? They’re doing great.”

“Buddy?” Gaster asked confused, “You actually went ahead and named it?”

“Yeah, why not?” Sans shrugged, “He’s basically become our pet at home.”

“Our?” Gaster asked, he wasn’t aware that Sans lived with anyone.

“Me and my little bro.”

“Oh?” Gaster asked, interested, “You have a brother?”

“Yeah, his name’s Papyrus.” Sans smiled.

“I see.”

“What about you Dr. Gaster?” Sans asked, “You got any siblings?”

“Um, no I’m afraid not.”

They fell into another silence and Sans began to notice how awkward it was.

“You know, I didn’t think the little guy was gonna like the snow all too much.” Sans started, “But I guess you could say it was love at frost sight.”

Silence, Sans began to panic. Then suddenly he heard a small laugh, he looked up at Gaster who was currently trying to stifle a laugh.

“Oh? So you like puns?” Sans asked, “How about this one, why isn’t energy made of atoms?”

“Hm.” Gaster smiled, “Why?”

“Oh, it doesn’t matter.”

Gaster finally let out a laugh, “That was a good one.”

“Well people do say I’m pretty humerus.” 

Gaster laughed again and Sans kept going, they went on like that until Asgore walked through the door.

“I’m sorry I’m late my friend, I’m afraid I had some business to attend to.” Asgore apologized, looking very tired.

“Hello King Fluffyboy.” Sans smiled at the tall goat.

Gaster immediately began to panic, how could Sans say something like that!? How could he be so disrespectful towards the king!? Just as Gaster was about to reprimand Sans for talking to the king like that, Asgore interrupted him with a laugh.

“It’s good to see that you haven’t lost your sense of humor, Sans.” Asgore grinned.

“‘Course not, I’ll die before I lose that.” Sans chuckled and Asgore joined him.

“Now then,” Asgore said, walking up to the two, “Shall we get our meeting started?”

-

After the meeting Asgore had sent them back to the lab to retrieve their things so that they could leave for the day. Gaster was getting ready to walk away when he heard Sans’ voice.

“Hey, Dr. Gaster.” Sans said, “A second?”

Gaster turned to look at his assistant.

“I just, I don’t really know if you care but here.” Sans handed him a piece of paper.

“What’s this?” Gaster opened the paper to see a series of numbers.

“My number.” Sans said, putting his hands in his pocket, “You know, in case you need to reach me.”

Gaster thought for a moment and put the paper away in his coat pocket, “Thank you Sans, I’ll keep this in mind.”

“Yeah, just know that anybody that can appreciate a good joke is a friend to me.” Sans smiled sheepishly.

Gaster smiled back, it made him feel good that he had someone else to potentially call a friend.

“Goodnight Sans.”

“Goodnight Dr. Gaster.”

-

Gaster had arrived at a dark and empty house, he felt alone again as he went to go sit at his recliner. His foot bounced up and down as he sat there restless, he felt like he should do something to keep his mind occupied. He got up and picked up one of his books to read, he tried to get through a few pages but he was struggling to stay focused. He suddenly felt hot and decided to take off his coat, as he did, a piece of paper fell out of one of his pockets. He leaned down to grab it and saw that it was Sans’ phone number, he picked it up and took in a deep breath. He may as well try calling the skeleton since he can’t focus on anything else, he entered the skeleton’s phone number into his contacts and hit the call button. 

“Hello?” Sans said as he answered.

“Ah, hello Sans.” Gaster said, “I just wanted to call you to, um…”

‘Why did I even think this was a good idea again?’ Gaster thought to himself.

“Give me your phone number?” Sans asked.

“Yes, that!” Gaster let out a small laugh, “I apologize, I’m not too good with talking on the phone.”

“That’s fine Doctor.” He could almost hear Sans’ smile, “Tiba honest, I’m not the best at calls either.”

Gaster stifled a laugh.

“SANS! NO!” A voice came from the background, “NOT IN FRONT OF MY VERY COOL FRIEND.”

“Sorry bro, just talking to my boss.” Sans said to his brother.

“YOU SHOULDN’T TALK TO YOUR BOSS LIKE THAT.” 

“It’s fine bro, you and your friend go have fun.”

“Sorry about that.” Sans said returning to the conversation with Gaster, “My bro’s got a friend from town over for tonight.”

“Ah, I hope I wasn’t intruding too much then.” Gaster said, suddenly feeling a little guilty.

“Naw you’re good.” Sans said, “I was just about to make them dinner is all.”

“Hm, then I suppose I’ll let you get to it.” Gaster said walking to his kitchen, “I myself haven’t eaten yet.”

“Alright doc- I mean Dr. Gaster.”

“Just call me Gaster.”

“Alright Gaster, goodnight.”

“Goodnight Sans.”


	6. Chapter 6

Things continued normally for Sans and Gaster for the next two weeks, they started to talk more during the day but messaging each other after work is where they really talked. They felt more comfortable opening up over text, or rather Gaster felt more comfortable. Things were going good in Gaster’s opinion, they officially considered each other a friend and got along fairly well. The two were currently walking out of the lab together, laughing at a joke that Sans had made.

“Hey Gaster?” Sans started, “I wanted to ask you a question.”

“Yes Sans?” Gaster looked down at his assistant.

“Well, I was wondering if you wanted to hang out together tomorrow.” Sans smiled, “You know, since it’s the weekend and all.”

Gaster went silent. He wasn’t good with people in a social setting, one could even say he’s awful at social interaction. Spending that amount of time with Sans alone would be completely different from working, at least at work he had the excuse of being too busy to talk but out of it? That could be a disaster. Then again, he and Sans did get along fairly well now that they were actually talking. Would it be rude to reject Sans’ offer? Would he be offended? What if things went smoothly and the two of them became even better friends?

“Gaster?” Sans asked a bit dejected, “It’s fine if you don’t want to.”

“No!” Gaster let out, “I do want to, I was just thinking.”

“Ok, I’ll text you where I live later.” Sans started to walk away, “Sorry that we can’t hang out somewhere cooler but I gotta be home for my brother.”

“That’s fine!” Gaster called out, “I’ll talk to you later Sans.”

-

Gaster hugged himself tighter, focusing on the crunch of the snow under his boots in an attempt to distract himself from the cold as he walked through the small town. He suddenly wished that he had the Riverperson take him to Waterfall instead of braving the cold, he’d rather be wet then freezing. At least the people of Snowdin were nice, they would give him a friendly wave and say hello to him. He had no idea why Sans would choose here to live in all the underground. He walked up to the doorstep of the skeleton’s home and took in a deep breath, letting the air sting his insides, and knocked on the door. He heard scuttling from behind the door and then suddenly the door opened to reveal the small skeleton, he was dressed in his usual day off clothing but complete with fuzzy pink slippers. 

“Hey Gaster.” Sans smiled, “Glad you could make it.”

Gaster stopped himself from checking out his assistant anymore then he already had and looked at Sans’ face, “Ah, hello Sans.” He said nervously, “Yes I’m glad I could make it also, I just wished you lived somewhere a bit warmer.”

“Sorry about that, should’ve warned you that it was gonna be this cold.” Sans stepped to the side to allow the taller man inside, “Only rule we got is that you gotta take your shoes off at the door, my bro doesn’t like cleaning up the snow.”

“I would agree with him, lest you have a slippery floor.” Gaster said entering the house and taking off his shoes as he was told.

“Yeah, wouldn’t want anyone slipping.” Sans laughed.

“BROTHER, WHO WAS AT THE DOOR?” A short skeleton appeared at the top of the stairs from out of a room.

“It’s just my boss, bro.” Sans called up to his brother, “Your friend ain’t here yet.”

The small skeleton walked back into the room he came out of, Sans turned to Gaster.

“Sorry about that, my bro’s waiting on someone too.” 

“Ah, sounds like they’re going to be having fun.”

“Yeah.” Sans said.

They fell into an awkward silence. Sans began to sweat slightly.

“So uh, you wanna watch something on tv?” Sans asked, “Or we could play a game?”

“A game sounds fun, what do you have.” Gaster smiled.

“I’m guessing you’re more of a board game kinda guy?” Sans said walking towards the kitchen.

“Yes, I’m afraid I haven’t really gotten too into video games.” Gaster followed him.

“We have Scrabble, Guess Who, Monopoly, and Battleships.” Sans said going to the cabinet, “Go ahead and take a seat at the table.”

“Battleships sounds like it would be good.” Gaster said, taking a seat.

Sans pulled the box out and walked over to the table, he set it up fairly quickly and took his seat across from Gaster.

“You ready to get dunked on?” Sans grinned.

“In your dreams.” Gaster rolled his eyes.

A heated game of Battleships began, both of them ruthlessly went after each other’s ships. Sans was down three ships and Gaster was down four.

“E3.” Gaster said, staring Sans in the eyes.

“Hit.” Sans breathed out, “You sunk my battleship.”

“Getting nervous Sans?” Gaster smirked, “You only have one left.”

“So do you doc.”

“That may be true.” Gaster started, “Alas, you still have yet to hit it once and I’ve managed to hit yours once.”

“Oh yeah well-”

Suddenly there was a knock at the door. Sans got up to see who it was and Gaster, like a lost puppy, followed right behind him. Sans opened the door to reveal a sentient flame in winter clothes and glasses, Gaster assumed by his age that this is the friend that Papyrus was talking about.

“Hey there Grillby, come on in.” Sans stepped aside to let the boy in, “You want me to take your scarf?”

“No thank you Sans, that’s fine.” The boy said in a quiet whisper-like voice.

“HELLO GRILLBY!” Came Papyrus’ voice from the top of the stairs, “I’M SO GLAD THAT YOU’RE HERE.”

The boy waved up at the short skeleton and began to walk up the stairs.

“WE’RE GOING TO GO HANG OUT IN MY ROOM BROTHER.” Papyrus announced before leading Grillby into his room.

Sans laughed then looked over at Gaster, who just stood there slightly tapping his foot out of nerves, he smiled and walked past the doctor.

“Come on G, games not gonna finish itself.” Sans gave Gaster a smirk as he took his seat.

“G?” Gaster asked, going to sit back down.

“Yeah, still tryna come up with a nickname for you.” Sans shrugged, “Why, you don’t like that one either?”

Gaster thought for a moment.

“I suppose I don’t mind it.”

-

“OK, SO WHAT DO YOU WANT TO DO TODAY?” Papyrus smiled as he closed his door and turned to look at the other boy.

“Who was that with your brother?” Grillby asked.

“OH, HIM?” Papyrus asked, “THAT’S JUST MY BROTHER’S BOSS.”

“His boss?” Grillby tilted his head in confusion, “Why is he here?”

“I THINK SANS SAID THAT THEY WERE HANGING OUT?” 

“Isn’t that what we say when we wanna go on a date?”

“WELL, YES.” Papyrus stopped for a moment. “WAIT, DO YOU THINK THAT THEY’RE DATING TOO?”

“Maybe that’s why they’re together outside of work too.” Grillby rubbed his chin thoughtfully, “Maybe he’s his boyfriend?”

“WHY HASN’T HE TOLD ME?” Papyrus looked saddened.

“Have you told him about us?”

“WELL, NO.”

“Why not?”

“I DON’T KNOW HOW HE WILL REACT.” Papyrus scratched the back of his neck in embarrassment. 

“Maybe that’s why he hasn’t told you either.” Grillby said, “He might just be scared.” 

Papyrus pouted slightly.

“SHOULD I ASK HIM ABOUT IT AFTER THE TWO OF YOU GO HOME?”

“Maybe, I think you should think about telling him about us soon.” Grillby took Papyrus’ hand in his own, “I don’t like having to sneak around.”

“OK, I WILL TRY TO TELL HIM LATER.” Papyrus said pressing his teeth against where Grillby’s cheek would be in an attempt to give him a kiss.

-

Gaster had left about a half an hour after Grillby had to go home, once Papyrus was sure that the tall man was gone he went downstairs where he found his brother watching tv. 

“SANS CAN I ASK YOU A QUESTION?” Papyrus started, “AND POSSIBLY TELL YOU SOMETHING?”

“Yeah, what’s up bro?” Sans asked, turning down the tv and took a sip of water.

“IS DR. GASTER YOUR BOYFRIEND?” 

Sans choked.

“What!?”

“IS HE YOUR BOYFRIEND, AND WERE YOU HAVING A DATE TONIGHT?”

“No bro, he’s not my boyfriend and this wasn’t a date.” Sans said, “We’re just friends.”

“OH, I SEE.”

“What gave you that idea.”

“NO REASON, GRILLBY THOUGHT IT WAS A DATE.”

“Alright... so what did you want to tell me?”

“UM, WELL.” Papyrus began to sweat.

“It’s ok bro, what do you wanna tell me?”

“I- I’M HUNGRY FOR DINNER.”

“Already?”

“YES, IT’S VERY TIRING HAVING SUCH A COOL FRIEND OVER TO SPEND TIME WITH.” 

“Ok…” Sans got up off the couch, “I’ll start on dinner I guess.”

**Notes for the Chapter:**

> i just like papby ok?


End file.
